Campbell Biology Ch. 22-24 - Evolution Unit Flashcards

Inherited characteristic of an organism that enhances its survival and reproduction in specific environments.

Aristotle

Developed the first classification system for organisms, was not based on shared ancestry, rather based on similar characteristics or habitats

Artificial selection

The selective breeding of domesticated plants and animals to encourage the occurrence of desirable traits.

Binomial nomenclature

a system of naming organisms that includes a two-part latinized name of a species, consisting of the genus and specific epithet.

Biogeography

The study of the past and present distribution of species.

Catastrophism

The principle that events in the past occurred suddenly and were caused by different mechanisms than those operating today

Continental drift

The slow movement of the continental plates across Earth’s surface.

Convergent evolution

The evolution of similar features in independent evolutionary lineages.

Cuvier

proposed the Theory of Catastrophism

Darwin

Proposed the theory of evolution that attributed change to natural selection; cited finches in the Galopagos islands as evidence

Embryonic homologies

homologous structures present in the embryonic/developing forms of an organism only due to a shared common ancestor

Endemic species

Referring to a species that is confined to a specific, relatively small geographic area.

Gradualism

In the fossil record, when a species undergoes little morphological changes from generation to generation, causes overall change a lttle bit at a time. (opposite of catastrophism)

Homologous structures

Structures in different species that are similar because of common ancestry.

Homology

Similarity in characteristics resulting from a shared ancestry.

Hutton

Stated that current geologic processes can be used to explain past geologic processes

Lamarck

Proposed theory of evolution that involved the inheritance of acquired characteristics

Linnaeus

developed the modern classification system & latin based naming system (binomial nomenclature) for use in naming species

Lyell

used Hutton's ideas along with his own to form the principle of Uniformitarianism, which states the mechanisms of change are constant over time (Opposite of catastrophism)

Malthus

species are capable of producing more than their envidonment can support = struggle for existance

Molecular homologies

similarities in the genetic code/genes of species due to a shared ancestor

Natural selection

A process in which organisms with certain inherited characteristics are more likely to survive and reproduce than are organisms with other characteristics.

Paleontology

The scientific study of fossils.

Population

A localized group of individuals of the same species that can interbreed, producing fertile offspring.

Taxonomy

A scientific discipline concerned with naming and classifying the diverse forms of life.

Uniformitarianism

The principle stating that mechanisms of change are constant over time. The opposite of Catastrophism.

Vestigial organs

A structure of marginal, if any, importance to an organism. Vestigial structures are historical remnants of structures that had important functions in ancestors.

Wallace

developed a theory of evolution similar to that of Darwin; cited frogs in the East Indies as evidence

Bottleneck effect

Genetic drift that occurs when the size of a population is reduced, as by a natural disaster or human actions. Typically, the surviving population is no longer genetically representative of the original population.

Chromosomal mutation

changes in the genetic code of an organism caused by changes to large segments of a chromsome ( usually during crossing over) such as deletion, translocation, inversion or duplication

Clinal variation

a type of geographical variation that occurs as a gradual change in variation along a geographical axis

Diploidy

occur when an organism has 2 complete sets of the gentic code (one from each parent) - this allows for genetic recombination when shuffling of genes occurs when a new organism is produced. This also helps stabilize the effects of recessive genes by allowing organisms to have another gene that can block it out.

Directional natural selection

Natural selection in which individuals at one end of the phenotypic range survive or reproduce more successfully than do other individuals.

Disruptive natural selection

Natural selection in which individuals on both extremes of a phenotypic range survive or reproduce more successfully than do individuals with intermediate phenotypes.

Founder effect

Genetic drift that occurs when a few individuals become isolated from a larger population and form a new population whose gene pool composition is not reflective of that of the original population.

Frequency dependent selection

A decline in the reproductive success of individuals that have a phenotype that has become too common in a population.

Gene flow

The transfer of alleles from one population to another, resulting from the movement of fertile individuals or their gametes.

Gene pool

The aggregate of all of the alleles for all of the loci in all individuals in a population. The term is also used in a more restricted sense as the aggregate of alleles for just one or a few loci in a population.

Genetic drift

A process in which chance events cause unpredictable fluctuations in allele frequencies from one generation to the next. Effects of genetic drift are most pronounced in small populations.

Genetic variation

differences between the gene pools of populations or population subgroups.

Geographic variation

Differences between the gene pools of geographically separate populations or population subgroups.

Hardy-Weinberg theorem (equations)

p + q = 1 P2 + 2Pq + q2 = 1

Hardy-Weinberg theorem (use/purpose)

The condition describing a nonevolving population (one that is in genetic equilibrium). Since this doesn't occur in nature, it is used as a null hypothesis to determine the cause of change in a population.

Selection whereby individuals of one sex (usually females) are choosy in selecting their mates from individuals of the other sex; also called mate choice.

Microevolution

Evolutionary change below the species level; change in the allele frequencies in a population over generations.

Mutations

A change in the nucleotide sequence of an organism’s DNA, ultimately creating genetic diversity. Mutations also can occur in the DNA or RNA of a virus.

Neutral variation

Genetic variation that does not appear to provide a selective advantage or disadvantage.

Point mutation

occurs when one nucleotide in a gene sequence is changed

Polymorphic

refers to having multiple forms of a genetic variation within a population

Population genetics

The study of how complex interactions between biotic and abiotic factors influence variations in population size.

Quantitative characters

A heritable feature that varies continuously over a range rather than in an either-or fashion.

Relative fitness

The contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals in the population.

Sexual dimorphism

Marked differences between the secondary sex characteristics of males and females.

Stabilizing natural selection

Natural selection in which intermediate phenotypes survive or reproduce more successfully than do extreme phenotypes.

Discrete characters

A heritable feature that has clear "either-or" basis that clearly sets the varieties apart.

Adaptive radiation

Period of evolutionary change in which groups of organisms form many new species whose adaptations allow them to fill vacant ecological roles in their communities.

Allopatric speciation

The formation of new species in populations that are geographically isolated from one another.

Autopolyploid

An individual that has more than two chromosome sets that are all derived from a single species. Caused by nondisjunction in meiosis

Behavioral isolation

2 species who live in the same geographic area are isolated from reproducing due to differences in courtship behaviors or mate slection preferences.

Biogeography

The study of the past and present distribution of species.

Biological species concept

Definition of a species as a population or group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring, but do not produce viable, fertile offspring with members of other such groups.

Ecological species concept

views a species in terms of its ecological niche, 2 populations that fill a different niche in an area may be seen as 2 different species.

Gametic isolation

occurs when sperm from one species is not able to fertilize the egg of another, causes may be that it can't survive in the environment provided by the reproductive tract of the female of another species, or the sperm can't penetrate the egg due to biochemical mechanisms

Gene flow

The transfer of alleles from one population to another, resulting from the movement of fertile individuals or their gametes.

Genealogical/Phylogenetic species concept

A definition of species as the smallest group of individuals that share a common ancestor, forming one branch on the tree of life

Habitat isolation

2 species who live in the same geographic area are isolated from reproducing due to living in different habitats within the region, so they don't encounter each other to breed.

Hybrid breakdown

hybrids produced by the reproduction of 2 different species are fertile, but 2nd generation offspring are sterile or less viable. This prevents them from passing on the abnormal chromosome numbers that they were born with.

A definition of species in terms of measurable anatomical criteria (physical form)

Paedomorphosis

The retention in an adult organism of the juvenile features of its evolutionary ancestors.

Polyploidy speciation

when autopolyploids caused by nondisjunction are able to breed with each other but not members of their parent generations due to differences in chromosome numbers, so they become their own species

Postzygotic barriers

A reproductive barrier that prevent hybrid zygotes produced by two different species from developing into viable, fertile adults.

Prezygotic barriers

A reproductive barrier that impedes mating between species or hinders fertilization if interspecific mating is attempted.

Punctuated equilibrium

In the fossil record, long periods of apparent stasis, in which a species undergoes little or no morphological change, interrupted by relatively brief periods of sudden change. (opposite of gradualism)

Reduced hybrid fertility

hybrids produced by the reproduction of 2 different species are often sterile due to differing numbers of chromosomes in the parents. This prevents them from passing on the abnormal chromosome numbers that they were born with.

Reduced hybrid viability

the genes of 2 species may interact in such a way that they impair the hybrid's development or survival in it's environment

Reproductive isolation

The existence of biological factors (barriers) that impede members of two species from producing viable, fertile offspring.

Speciation

An evolutionary process in which one species splits into two or more species.

Sympatric speciation

The formation of new species in populations that live in the same geographic area.

Temporal isolation

2 species who live in the same geographic area are isolated from reproducing due to being active at 2 different times of the day/night, so they don't encounter each other to breed.

“Evo-devo”

a field of biology that compares the developmental processes of different organisms to determine the ancestral relationship between them, and to discover how developmental processes evolved.

Adaptive radiation

Period of evolutionary change in which groups of organisms form many new species whose adaptations allow them to fill vacant ecological roles in their communities.

Biogenesis

the theory that state that living things are produced by other living things

Endosymbiotic hypothesis

states that early eukaryotic organisms could have formed by infolding prokaryotic of membranes and the engulfing of other prokaryotes

Fossil record

the sequence of events & life forms shown by successive layers of sedimentary rocks deep into Earth's surface that acts as a timeline of events for geologists

Heterochrony

Evolutionary change in the timing or rate of an organism’s development.

Homeotic genes

Any of the master regulatory genes that control placement and spatial organization of body parts in animals, plants, and fungi by controlling the developmental fate of groups of cells.

Hox genes

A type of homeotic genes that gives a cell positional information in an embryo so that it can develop appropriate body parts in the right places

Miller & Urey

experimented to replicate the early reducing atmosphere and produced a variety of amino acids

Oparin & Haldane

Theorized that Earth's early atmosphere was a reducing atmosphere in which organic compounds could have formed from simple molecules

Protobionts

A collection of abiotically produced molecules surrounded by a membrane or membrane-like structure.

Radiometric dating

A method for determining the absolute ages (numeric age) of rocks and fossils, based on the half-life of radioactive isotopes.

Relative dating

A method of determining the age of an object compared to the ages of other objects, helps determine a sequence of events

Spontaneous generation

The theory that state that living things can be produced by nonliving materials